# US 2025/0154787 A1 · Underwater cleaner > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0154787 A1 - Document ID: US20250154787A1 - Status: Published application - Kind: A1 - Application number: 18/941,119 - Filed: 2024-11-08 - Published: 2025-05-15 - Earliest claimed: 2023-11-09 - Inventors: Andrés Fränkel; Benjamin Fränkel; Constantin Fränkel - Web page: https://patentgrep.com/patent/US20250154787A1 ## CPC - E04H 4/1654: {Self-propelled cleaners} - E04H 4/1636: {Suction cleaners} - E04H: BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL (foundations E02D) ## Abstract The invention relates to an underwater cleaner having a housing in which a pump, in particular a battery-operated pump, with an electric motor and an axial impeller rotatable about an axis of rotation is arranged, having a suction nozzle formed by the housing with a suction mouth defining a suction plane and a flow channel which is arranged in the housing accommodates the axial impeller and extends between a channel inlet opening arranged in the region of the suction nozzle and a channel outlet opening, wherein a receptacle for a filter device is arranged in the region of the channel outlet opening, and wherein the flow center axis of the flow channel is arranged perpendicular to the suction plane in a first section having the channel inlet opening and parallel to the suction plane in a second section having the channel outlet opening, and wherein the axial impeller is arranged in the first section of the flow channel, and wherein a first distance between a reference plane tangent to a lower channel wall of the second section normal to the axis of rotation of the axial impeller and the suction plane is smaller than the impeller radius. A compact underwater cleaner with a high suction effect can be realized if the reference plane intersects the axial impeller in at least one region of the impeller blades and at least one impeller blade projects beyond the reference plane by a defined projection. ## Claims ### Claim 1 An underwater cleaner, in particular for a swimming pool, comprising: a housing, in which a pump, in particular a battery-operated pump, with an electric motor and an axial impeller rotatable about an axis of rotation is arranged, having a suction nozzle formed by the housing with a suction mouth defining a suction plane and a flow channel which is arranged in the housing, accommodates the axial impeller and extends between a channel inlet opening arranged in the region of the suction nozzle and a channel outlet opening, wherein a receptacle for a filter device is arranged in the region of the channel outlet opening, and wherein the flow center axis of the flow channel is arranged perpendicular to the suction plane in a first section having the channel inlet opening and parallel to the suction plane in a second section having the channel outlet opening, and wherein the axial impeller is arranged in the first section of the flow channel, and wherein a first distance between a reference plane tangent to a lower channel wall of the second section normal to the axis of rotation of the axial impeller and the suction plane is smaller than the impeller radius, wherein the reference plane intersects the axial impeller in at least one region of the impeller blades and at least one impeller blade projects beyond the reference plane by a defined projection. ### Claim 2 (depends on 1) The underwater cleaner according to claim 1, wherein the first distance is at most 80 of the impeller radius. ### Claim 3 (depends on 1) The underwater cleaner according to claim 1, wherein a second distance (b) between the reference plane (δ) and the channel inlet opening of the flow channel is at most 50%, preferably at most 40%, particularly preferably at most 37%, of the impeller radius (r). ### Claim 4 (depends on 1) The underwater cleaner according to claim 1, wherein the axial impeller is arranged in the region of the channel inlet opening of the flow channel. ### Claim 5 (depends on 1) The underwater cleaner according to claim 1, wherein the axial impeller is arranged in the region of the reference plane (δ). ### Claim 6 (depends on 1) The underwater cleaner according to claim 1, wherein the projection is about 10%±2% of the impeller radius. ### Claim 7 (depends on 1) The underwater cleaner according to claim 1, wherein the flow channel has, in the transition between the first section and the second section, an outer bend area with a first radius of curvature (k1) which is smaller than the impeller radius (r), preferably smaller than half the impeller radius (r). ### Claim 8 (depends on 7) The underwater cleaner according to claim 7, wherein the first radius of curvature is at most 25 of the impeller radius. ### Claim 9 (depends on 1) The underwater cleaner according to claim 1, wherein the underwater cleaner in the second section has a rectangular cross-section with a height measured normal to the suction plane and a width measured parallel to the suction plane, wherein the height is at most 25%. ### Claim 10 (depends on 1) The underwater cleaner according to claim 1, wherein the suction nozzle has a layout deviating from a circular basic shape with a single-symmetrical suction mouth. ### Claim 11 (depends on 10) The underwater cleaner according to claim 10, wherein the suction mouth is two-winged, wherein a lateral wing area is arranged on either side of a central area. ### Claim 12 (depends on 11) The underwater cleaner according to claim 11, wherein the suction mouth has a depth extension measured in the direction of movement of the underwater cleaner and a width extension measured normal to the depth extension, wherein the largest depth extension measured in the central area is at least 50% of the largest width extension (W). ### Claim 13 (depends on 11) The underwater cleaner according to claim 11, wherein the central area comprises a second radius of curvature which is larger than the impeller radius. ### Claim 14 (depends on 11) The underwater cleaner according to claim 11, wherein the lateral wing areas each have a third radius of curvature which is smaller than the second radius of curvature of the central area, wherein the third radius of curvature (k3) is preferably at most ½, particularly preferably at most ⅓, in particular at most ¼ of the second radius of curvature (k2). ### Claim 15 (depends on 11) The underwater cleaner according to claim 11, wherein a fourth radius of curvature is formed between the two wing areas, which is at least twice as large as the second radius of curvature. ### Claim 16 (depends on 11) The underwater cleaner according to claim 11, wherein between the central area and each wing area, the suction mouth has a convex section, wherein the convex section forms a fifth radius of curvature, which corresponds to the second radius of curvature±20%.